<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			tr:first-child>td::before{
				content: "表头";
			}
			tr:nth-child(n+2)>td::before{
				content: "单元格";
			}
			
			/* tr:first-child~tr>td::before{
				content: "单元格";
			}第一行的普通兄弟
			 */
			
			tr:nth-child(2n){
				background-color: skyblue;
			}
			
			
		</style>
	</head>
	<body>
		<table border="1" cellspacing="0" width="400px" height="250px">
			<tr>
				<td></td>
				<td></td>
				<td></td>
				<td></td>
				<td></td>
			</tr>
			<tr>
				<td></td>
				<td></td>
				<td></td>
				<td></td>
				<td></td>
			</tr>
			<tr>
				<td></td>
				<td></td>
				<td></td>
				<td></td>
				<td></td>
			</tr>
			<tr>
				<td></td>
				<td></td>
				<td></td>
				<td></td>
				<td></td>
			</tr>   
			<tr>    
				<td></td>
				<td></td>
				<td></td>
				<td></td>
				<td></td>
			</tr>   
			<tr>    
				<td></td>
				<td></td>
				<td></td>
				<td></td>
				<td></td>
			</tr>   
			<tr>    
				<td></td>
				<td></td>
				<td></td>
				<td></td>
				<td></td>
			</tr>   
			<tr>    
				<td></td>
				<td></td>
				<td></td>
				<td></td>
				<td></td>
			</tr>
		</table>
	</body>
</html>
